Physics Flashcards
The earth is spinning at the rate of 9 rotations per second with a mass of 1.5 x 10^3. At what time will the earth stop spinning?
The world stops spinning when I look at you AHHAHAAHAHAHAHAHAH
This is the most fundamental branch in science. It is the nature of basic things, force, energy, matter and other. This branch of science supports other fields like biology and chemistry.
Physics
It is the closeness of measurement to the true value.
Accuracy
It is how close the measurement of the same item to each other.
Precision
What are the 2 types of Error in measurement?
Random error and Systematic error
Differentiate Random error and Systematic error.
Random error is the change of measurements due to the environment or measurement technique while systematic error is the change of measurements due to faulty instruments or incorrect handling of tools
It is anything that occupies space and has mass
Matter
It is the capacity of doing work.
Energy
What are the 2 properties of matter?
Physical Properties and Chemical Properties
This is the qualities that has magnitude only.
Scalar
This is the qualities that has magnitude and direction
Vector
Distance
Scalar or Vector?
Scalar
Speed
Scalar or vector?
Scalar
Weight
Scalar or vector?
Vector
Force
Scalar or vector?
Vector
What is the difference between speed and velocity?
Speed is how far an object travels within a period of time while velocity is how far an object travels within a period of time with direction.
Speed (scalar) and Velocity (vector)
This is the addition of vectors that is equivalent to composition of vectors and the sum of vectors.
Resultant of vectors
60km east + 40km east =
60 + 40 = 100km east
80m west + 90m east =
-80 + 90 = 10km east
80 is negative because it goes to west (left) and the answer is east because 90 is the larger vector
Vector u = (-2,5)
Vector w = (6,3)
1/3 w + 3 u = ?
=(-4,16)
```
Solution:
1/3(6,3) + 3(-2,5
2,1) + (-6,15)
2-6 = -4 (x)
1+15 = 16 (y)
~~~
Vector u = (5,-4)
Vector w = (-6,2)
-2w - 3u = ?
=(-3,8)
Vector u = (-8,1)
Vector v = (5,3)
-3v + 4u = ?
(-47, -5)
An airplane accelerates down a runway at 3.20 m/s/s for 32.8s until it finally lifts off the ground. Determine the distance traveled before takeoff.
d = 1720 m
Solution: a= 3.2m/s/s; t= 32.8s; Vi= 0m/s d= (Vi*t) + 1/2 (a*t) d= 0(32.8)+ 1/2 (3.20)(32.8) d= 1720m
A car starts from rest and accelerates uniformly over a time of 5.21s for a distance of 110m. Determine the acceleration of the car.
a = 8.10 m/s/s
Solution: d= 110m; t= 5.21s; Vi= 0m/s d= Vi*t + 1/2 a*t 110= (0)(5.21) + 1/2 a(5.21) 110= 13.57a a= 110/13.57 a= 8.10 m/s/s
Upton Chuck is riding the Giant Drop at Great America. If Upton free falls for 2.60s, what will be his final velocity and how far will he fall?
d = 33.1m and Vf= 25.5m/s
Solution: g= 9.8m/s/s; t= 2.6s; Vi= 0m/s d= Vo*t + 1/2 g*t^2 d= (0)(2.6) + 1/2 (9.8)(2.6^2) d= 33.1m Vf= Vo + g*t Vf= 0 + 9.8(2.6) Vf= 25.5 m/s
A race car accelerates uniformly from 18.5m/s to 46.1m/s in 2.47 seconds. Determine the acceleration of the car and the distance traveled.
a = 11.2 m/s/s and d = 79.8m
Solution: a= (Vf - Vo)/t a= (46.1 - 18.5)/2.47 a= 11.2 m/s/s d= Vo*t + 1/2 a*t d= (18.5)(2.47) + 1/2(11.2)(2.47) d= 79.8m
A feather is dropped on the moon from a height of 1.40m. The acceleration of gravity on the moon is 1.67m/s/s. Determine the time for the feather to fall to the surface of the moon.
t = 1.29s
Solution: Vo = 0; d = 1.40m; a = 1.67m/s/s d= Vo*t + 1/2 g*t 1.40= (0)(t) + 1/2 (1.67)*(t^2) 1.40=0.835t^2 t^2= 1.40/0.835 t= 1.29s
It is the total path length covered during a journey.
Distance
The path length from the final position of the particle to the origin 0.
Displacement
A car starting from rest began moving in a straight line from a fixed point. Its velocity after t seconds is given by
v = (8t^2 +6t) m/s , t>= 0(t is greater or equal to 0)
Calculate the displacement of the car when t = 9s
s = 2187m
chat me for solutions wenkwenk
A particle is moving in a straight line such that its velocity at time t seconds is given by
v = (15t^2 - 8t) m/s, t>= 0
Given that its initial position from a fixed point is 20m, find an expression for its displacement at time t seconds.
5t^3 - 4t^2 +20 m
A particle moves along the x-axis. At time t seconds it acceleration is given by
a = (4t + 6) m/s/s, t >= 0
Given that at t = 2s, its velocity is 28 m/s, what is its initial velocity?
Vo = 8m/s
A particle is moving in a straight line such that its acceleration at time t seconds is given by
a = (2t - 18) m/s/s, t >= 0
Given that its initial velocity is 20 m/s, find an expression for its displacement in terms of t.
(t^2 - 18t + 20)m
Stress ka?
Take a rest or chat me hehehe
A water balloon is thrown horizontally with a speed of 8.31 m/s from the roof of the building of 23m. How far does the balloon travel horizontally before striking the ground?
dy = 18m
Solution: Vx= 8.31m/s; dy= 23m dy= Voy*t + 1/2 g*t^2 23 = 0*t + 1/2 (9.8)(t^2) 23 = 1/2 (9.8)(t^2) 23 = 4.9 (t^2) 23/4.9 = t^2 t = square root of 23/4.9 t = 2.166535841s dx = vx*t dx = 8.31(2.17) dx = 18m
An air cannon is used to launch a pumpkin off a cliff of 18m with an initial velocity of 11.4m/s at an angle of 52.1. What is the vertical and horizontal component velocity?
Vx = 7 m/s and Vy = 9 m/s
A ball rolls horizontally off a cliff at 20m/s. It take 10s for it to hit the ground. Calculate the height of the cliff and the horizontal distance traveled by the ball.
dy = 490m and dx = 200
Solution: Vx = 20 m/s; t = 10s dy = Voy*t + 1/2 g*t^2 dy = 0*t + 1/2 (9.8)*(10^2) dy = 490m dx = Vx*t dx = 20(10) dx =200m
A ball is released from rest and drops straight down starting at a height of 800m. How long will it take to hit the ground?
t = 12.78s
Solution: dy = Voy*t + 1/2 g*t^2 800 = 0(t) +1/2 (9.8)(t^2) 800 = 4.9t^2 t^2 = 800/4.9 t = 12.78s
A ball is kicked off the ground at 40 m/s at an angle of 60 degrees. a) Find the Max. Height b) Calculate the time it takes to hit the ground c) Determine the range of the ball
h= 61.2m; t = 7.07s; R= 141.39m
A ball is kicked off the ground reaching a maximum height of 100m and lands 200m away. Calculate the initial speed and the angle above the horizontal of the ball when it was kicked.
Angle = 63.43 degrees and v = 49.5 m/s
This force pushes an object inward towards the center of the circular motion.
Centripetal Force
This is a fictitious force that pushes outward of the circular motion.
Centrifugal force
What is the magnitude of the centripetal force that must act on an object of mass 1.0kg to make it move along a circular path of a diameter 1.0m, completing a circle every 1.0s? Round off to the nearest newton.
Fc = 20N
Solution: m = 1kg ; r = 0.5m ; t = 1.0s Fc = mrw^2 w = 2pi/1s Fc = 1kg (0.5)(2pi/1s)^2 Fc = 20N
A ball is thrown with an initial velocity of 70 ft/s, at an angle of 35 degrees with the horizontal. Find the vertical and horizontal components of the velocity.
Horizontal = 57.34 ft/s and vertical = 40.15 ft/s
Solution:
v = 70 (cos (35))i + 70 (sin (35))j
v = 57.34i + 40.15j
A force is given by the vector F = (2,3) and moves an object from the point (1,3) to the point (5,9). Find the work done.
W = 26 ft-lb
Solution: d= (5-1, 9-3) = (4,6) W = F * D W = (2,3) * (4,6) W = 26
Calculate the centripetal force acting on a 925 kg car as it rounds an unbanked curve with a radius of 75cm at a speed of 22 m/s.
Fc = 6000 N
A small plane makes a complete circle with a radius of 3282m in 2.0 mins. What is the centripetal acceleration of the plane?
a = 9.0 m/s/s
How do find the velocity out of this equation?
Fc = mv^2/r
v = square root of F*r/m
How do you find time in this equation?
Vy = Voy - gt (vertical velocity of projectile)
t = (-Vy + Voy )/g
A car with a mass of 833kg rounds an unbanked curve in the road at a speed of 28.0 m/s. If the radius of the curve is 105m, what is the average centripetal force exerted on the car?
Fc = 6200 N
A motocorss rider at the peak of his jump has a speed such that his centripetal acceleration is equal to g. As a result, he does not feel any supporting force from the seat of his bike, which is also accelerating at the rate g. Therefore, he feels if there is no force of gravity on him, a condition described as apparent weightlessness. It the radius of approximately circular jump is 75.0m, what is the speed of the bike?
v= 27m/s
Solution: a = v^2/r v = square root of a*r (derived formula) v = square root of (9.8)(75.0) v=27m/s
